[libcxx-commits] [PATCH] D60368: Add bind_front function (P0356R5)

Louis Dionne via Phabricator via libcxx-commits libcxx-commits at lists.llvm.org
Tue Feb 9 08:47:39 PST 2021

ldionne requested changes to this revision.
ldionne added a comment.
This revision now requires changes to proceed.

I'll mark this as "requires changes" so it shows up properly in the queue.

Comment at: libcxx/test/std/utilities/function.objects/func.not_fn/not_fn.pass.cpp:149
 #if defined(_LIBCPP_VERSION)
-        ret = ret2;
-        assert(ret() == true);
-        assert(ret2() == true);
+        if (!std::is_constant_evaluated()) {
+            ret = ret2;
Quuxplusone wrote:
> zoecarver wrote:
> > @ldionne I did have one problem after rebasing. Because this is implemented with `std::tuple`, the assignment operator isn't constexpr. I see a few options here: 
> > 
> > 1. Wait to land this until we implement constexpr assignment operators for `std::tuple`.
> > 2. Add the above check (`is_constant_evaluated`) to this test and remove it once constexpr assignment operators for `std::tuple` are implemented.
> > 3. Just remove this part of the test entirely because it's not required by the standard. 
> > 4. Update `std::tuple` to have constexpr assignment operators (without properly implementing the paper).
> FWIW, I vote for #3 — `std::not_fn(x)` isn't supposed to be assignable. It might even be user-friendly to //delete// its assignment operator so that libc++ users don't start relying on it and then break when they move to a different STL vendor.
> Alternatively, provide and test the assignment operator but move the test into `test/libcxx/utilities/` instead??
Yeah, I agree with Arthur about doing (3).

  rG LLVM Github Monorepo



More information about the libcxx-commits mailing list